So a tree could produce this flower (3,4)
I believe the answer is:
tea rose
'this flower' is the definition.
(I've seen this before)
'so a tree could produce' is the wordplay.
'could produce' indicates anagramming the letters (I've seen this in other clues).
'so'+'a'+'tree'='soatree'
'soatree' is an anagram of 'TEA-ROSE'.
(Other definitions for tea rose that I've seen before include "Flowering bush" , "Garden plant" , "Eats roe (anag.)" , "Bloom" , "Scented garden flower" .)